Slow speeds supposed to get 2000 MBPS only getting approximatly 65 MBPS

I'm not getting the speed I am paying for, If i am only going to get the slower speed I want to down grade the account. Last week I attempted to get this fixed at that time I was getting approximately 250 MBPS before I upgraded I was getting 650 MBPS, and now it is at 65 MBPS. I seems impossible to get someone on the phone to address this issue, and when I do it only gets worse.